Rather than 'emotion', Western art was originally a way to impart knowledge to the illiterate masses.
Kings would stamp their faces on currency and spread it across their kingdoms, religious temples/churches/etc would use statues, mosaics and murals to teach lessons, stories, rules and beliefs.
Art was used to spread Ideas, and since Greece was the centre of Western culture, let's start there.
Ideas are beautiful in themselves, right? Plato thought a lot about beauty and Ideas. Is everyone familiar with his 'shadows on the cave wall' theory? Well, art was sort of a way to capture the Idea, which is perfect, unattainable, and impossible to completely copy/represent in corporeal form. And the Greeks were all about trying to create perfection/beauty through form. If you really examine art/architecture from this time/place, there's a whole heck of a lot of math going into it... the precision of ratio/etc is incredible.
So, if art was used to spread Ideas, then is 'good art' beautiful or useful?
The title of this post is a phrase by Immanuel Kant (1724-1804), describing the nature of beauty. In other words, something that is beautiful pleases us. This is different than us enjoying it for it's purpose/usefulness. Take, for example, a car. We can appreciate it based on the fuel economy, the amount of trunk space, the number of passengers it can hold, etc. Speed can also be a factor. While we don't necessarily need to go 0 to 60 in under six seconds, there can be a quality of purposefulness in the raw thrill of acceleration.
We can also enjoy cars based on their beauty, the lines of the body, the colour, the sound of the engine, the materials of the interior, etc. These don't add any usefulness to the vehicle, but even if cars really aren't your thing, I think anyone comparing an Audi Q7 and a Nissan Cube strictly on their body design would agree that the Audi is more beautiful than the Nissan.
A lot of money goes into making the 'package' pretty, but that doesn't mean it's 'better' if we're talking purely about purpose/usefulness.
Kant believed that to truly appreciate the 'beauty' of something, the person experiencing it must remain disinterested, in other words, receive no pleasure/sensation. It is the perfection of the object's form and design which we appreciate and approve of. So, no getting all googly-eyed at a French odalisk painting...
Taking this to a modern level, I could say there is beauty in a software engineer reducing 1,000 lines of computer code into 20 lines. The code may do the exact same thing, but it has been streamlined so there is no waste and no redundancies or overlaps. There is a kind of beauty in efficiency and precision.
According to Kant's theory, beauty was significantly different than aesthetics (aisthesis -> Greek for sensation/taste), which stimulates emotions, intellect and imagination.
So, he suggests there is a clear distinction between something that elicits emotion and something that is beautiful.
One other interesting contribution of Kant's was his idea of 'genius', essentially the ability to create harmony through their materials, thus resulting in the disinterested enjoyment of the beautiful end-result.
I think its important to remember that Kant, and his predecessor David Hume (1711-1776), lived during the Enlightenment period, the Age of Reason, where the prominent ideals were centred around progress, including the notion of moral improvement, human rights, and freedom of worship/religion. Because there was so much scientific advancement, classification of knowledge became important and the first dictionary and encyclopedia were published. There was also a huge renewed interest in Greek/Roman art during this time, mainly because Pompeii was being excavated, but also because Greece/Rome was where ideas of democracy/etc were born.
Many of these advancements came out because of the French Revolution, and France was the centre of the world for artists at this time, and up until modern times. King Louis XIV wanted to stamp out the uncultured dialects/etc, so he established the French Academy, not only to standardize the French language, but to standardize all manner of French culture, including art.
Remember at this time, artists were essentially craftsmen. Like hiring a carpenter to build a deck off your house, art was commissioned by the wealthy according to specific guidelines. So the fact that the king essentially controlled what was art is not something we, as modern humans, can really connect to. Our world is so much wider than it was back then.
Art was a bill-board for the uneducated.
Shame, awe, humility, honour, reverence, devotion, disgust, fear, peace, trust, loyalty.
Think this. Feel this. Know this.
It was not only an efficient way to sell Ideas, but to solidify the notion of class. Only those in power had/used art, so they were the ones controlling what messages art was sending.
Like how parking a ferrari in your driveway is a statement of your status, wealth, taste, values, etc, having the means and ability to buy/commission/use art was a measure of being in the elite.
I'm sure I'll annoy some people by simplifying to this degree, but this is a blog primarily tailored for other writers, not Art Historians, so I'm going to generalize and state, what was considered beautiful during that time was a lot of Greek/Roman iconography, historical or religious subjects.
Like how a ferrari is almost a universal statement of wealth/status/taste, so hanging a piece of art that associated you with the ideals of democracy/intelligence/reason/etc was a statement about who you were as a person. This is the same reason Hitler was obsessed with Greek/Roman art/etc and tried to push the idea that the Nazis were the true children of the Greeks. By associating himself with the ideas of that civilization, he was making the statement that he (and his people) were enlightened and better than other people.
The USA did a similar thing with association when they began building up their country. They didn't have to re-invent the wheel. By using eagles, columns, allegorical figures of liberty & freedom carved in the familiar Greek/Roman style, they were laying claim to those ideas, to those ideals, re-selling them as their own.
And there's absolutely nothing wrong with that. It's human nature to borrow where we can, 'cause it's efficient. Symbols are short-hand, like seeing a red maple leaf, most of the educated world would probably associate it with Canada, right?
Symbols are like an Idea distilled, and historically, Western art is all about ideas. You can take this right back into the very infancy of Western culture, far back before the Greeks.
In the Age of Reason, if something looked like Michelangelo made it, you were golden, so everyone just copied the same style. That is what sold. That is what was good. That is what made them successful and allowed them to feed their families. The other thing that was important is that the artist's hand was not visible. This means the brush strokes had no character. Paint was layered on in numerous, thin, floaty layers, not like the bold brushstrokes of more modern art. At this time in history, the artist wasn't supposed to show any part of themselves in the art.
Think of it like the voice of the author suddenly intruding into a story. It was a big no-no.
But that certainly changed.